Java tutorial
/** * '$RCSfile: DocumentHandler.java,v $' * * '$Author: leinfelder $' * '$Date: 2008-08-08 21:40:51 $' * '$Revision: 1.2 $' * * For Details: http://ecoinformatics.org * * Copyright (c) 2008 The Regents of the University of California. * All rights reserved. * * Permission is hereby granted, without written agreement and without * license or royalty fees, to use, copy, modify, and distribute this * software and its documentation for any purpose, provided that the * above copyright notice and the following two paragraphs appear in * all copies of this software. * * IN NO EVENT SHALL THE UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY PARTY * FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN * IF THE UNIVERSITY OF CALIFORNIA HAS BEEN ADVISED OF THE POSSIBILITY * OF SUCH DAMAGE. * * THE UNIVERSITY OF CALIFORNIA SPECIFICALLY DISCLAIMS ANY WARRANTIES, * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE * PROVIDED HEREUNDER IS ON AN "AS IS" BASIS, AND THE UNIVERSITY * OF CALIFORNIA HAS NO OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, * UPDATES, ENHANCEMENTS, OR MODIFICATIONS. */ package edu.lternet.pasta.dml.download; import java.io.IOException; import java.io.InputStream; import java.io.PipedInputStream; import java.io.PipedOutputStream; import java.net.URL; import java.util.concurrent.ExecutorService; import java.util.concurrent.Executors; import java.util.concurrent.TimeUnit; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.ecoinformatics.ecogrid.authenticatedqueryservice.AuthenticatedQueryServiceGetToStreamClient; import org.ecoinformatics.ecogrid.queryservice.QueryServiceGetToStreamClient; public class DocumentHandler { public static Log log = LogFactory.getLog(DocumentHandler.class); private String docId = null; private EcogridEndPointInterface ecogridEndPointInterface = null; private PipedInputStream inputStream = null; private PipedOutputStream outputStream = null; public DocumentHandler() { //initialize the streams for reading the document from server outputStream = new PipedOutputStream(); inputStream = new PipedInputStream(); try { outputStream.connect(inputStream); } catch (IOException e1) { log.error("could not connect piped streams! " + e1.getMessage()); e1.printStackTrace(); } } public InputStream downloadDocument() throws Exception { log.info("starting the download"); boolean success = true; final String id = docId; final EcogridEndPointInterface endpoint = ecogridEndPointInterface; ExecutorService service = Executors.newSingleThreadExecutor(); service.execute(new Runnable() { public void run() { long startTime = System.currentTimeMillis(); //get from the ecogrid try { if (ecogridEndPointInterface instanceof AuthenticatedEcogridEndPointInterface) { AuthenticatedQueryServiceGetToStreamClient authenticatedEcogridClient = new AuthenticatedQueryServiceGetToStreamClient( new URL(((AuthenticatedEcogridEndPointInterface) endpoint) .getMetacatAuthenticatedEcogridEndPoint())); authenticatedEcogridClient.get(id, ((AuthenticatedEcogridEndPointInterface) endpoint).getSessionId(), outputStream); } else { QueryServiceGetToStreamClient ecogridClient = new QueryServiceGetToStreamClient( new URL(endpoint.getMetacatEcogridEndPoint())); ecogridClient.get(id, outputStream); } outputStream.close(); long endTime = System.currentTimeMillis(); log.debug((endTime - startTime) + " ms to download: " + docId); log.debug("Done downloading id=" + id); } catch (Exception e) { log.error("Error getting document from ecogrid: " + e.getMessage()); e.printStackTrace(); } } }); //wait for the download to complete service.shutdown(); service.awaitTermination(0, TimeUnit.SECONDS); return inputStream; } public String getDocId() { return docId; } public void setDocId(String docId) { this.docId = docId; } public EcogridEndPointInterface getEcogridEndPointInterface() { return ecogridEndPointInterface; } public void setEcogridEndPointInterface(EcogridEndPointInterface ecogridEndPointInterface) { this.ecogridEndPointInterface = ecogridEndPointInterface; } }